The abhidharma worldview … analyzed humans and their surrounding world in detail. First, the world is divided into three realms or the triple world: (1) the desire realm in which individuals exist with desires for sex and food, (2) the form realm in which individuals have left behind the above two desires but are not free from material restrictions, (3) the formless realm as spiritual since it is free from material restrictions. It is held that the desire realm contains the six paths (or five paths if asura are not included): hell-dwellers, hungry ghosts, animals, demigods called fighting demons (asuras), and humans. There are also the six heavens of the desire realm: Heaven of the Four Heavenly Kings, Heaven of the Thirty-three Gods, Yāma or Heaven of Time, Tuṣita or Heaven of Contentment, Heaven of Delight in Creation, and Heaven of Controlling the Creation of Others. In the form realm are seventeen heavens. First is the group of the heavens of the first meditative concentration: Heaven of Brahma’s Retainers, Heaven of Brahma’s Ministers, and Great Brahma’s Heaven. The next grouping is the heavens of the second meditative concentration: Heaven of Lesser Radiance, Heaven of Immeasurable Radiance, and Heaven of the Ultimate Radiance. The third grouping is the heavens of the third meditative concentration: Heaven of Lesser Purity, Heaven of Immeasurable Purity, Heaven of Pervasive Purity. The last grouping is the heavens of the fourth meditative concentration: Cloudless Heaven, Heaven of Meritorious Birth, Heaven of Extensive Fruition, Heaven Free from Afflictions, Heaven Without Torment, Heaven of Perfect Form, Heaven of Perfect Vision, and the Highest Heaven. Lastly in the formless realm are four heavens: Heaven of Infinite Space, Heaven of Infinite Consciousness, Heaven of Nothingness, and Heaven of Neither Perception nor Non-Perception.

The term abhidharma consists of “dharma” with the prefix “abhi,” which means “towards.” It means “approaching the Dharma,” or “Dharma analysis.” From around the second century BCE, interpretations of Śākyamuni’s teachings were written and gradually systematized in the form of treatises. These included what are referred to as the “six treatises”: (1) the Saṃgītiparyāyapādaśāstra or Pronouncements Treatise. This is based on the text translated into Chinese as the Shòngji jing or Communal Recitation Sūtra. It organizes doctrines using groups of dharmas, or phenomena, with sections numbering from one to ten. (2) the Dharmaskandhapādaśāstra or Aggregation of Factors Treatise. This explains doctrines such as the path of religious training, delusion, and various dharmas with quotes from the Buddha’s teachings. (3) the Prajñāptipādaśāstra or Designations Treatise. This establishes a worldview centered on Mt. Sumeru. (4) the Vijñānakāyapādaśāstra or Collection on Consciousness Treatise. This expounds a theory of consciousness that uses the doctrine of the “triple world of saṃsāra”: the mundane world of birth and death, and the “three natures”: good, evil, and neither good nor evil. (5) the Dharmaskandhapādaśāstra or Treatise on the Collection of Elements. This categorizes mental factors into “omnipresent,” “major afflictions,” “minor afflictions,” and other groupings. (6) the Prakaravapādaśāstra or Exposition Treatise. This further develops the topics in the previous five treatises and organizes all dharmas.

Maitrīkaruṇā, or compassion, is one of the major virtues in Buddhism. Maitrī means loving-kindness or affection, and karuṇā means compassion or sympathy. The former is said to be the providing of comfort, and the latter the removing of suffering. This way of thinking about compassion was systematized into the “four immeasurable minds”: (1) loving-kindness: providing comfort to sentient beings, (2) compassion: removing suffering, (3) sympathetic joy: taking joy in sentient beings’ suffering having been removed, and (4) equanimity: leaving behind love and hatred. Buddhism preaches putting compassion into practice based on these four states of mind.

The term saṃgha means “something gathered,” “assembly,” and similar ideas. It is sometimes translated into Chinese as zhòng, which means congregation. In Buddhism, it refers to the group of religious trainees. Along with the Buddha and the Dharma it is considered one of the Three Treasures. The saṃgha is comprised of the following: (1) bhikṣu: fully ordained renunciate male religious trainees, (2) bhikṣuṇī: fully ordained renunciate female religious trainees, (3) śramaṇera: male renunciates who have not yet been fully ordained, (4) śramaṇerī: female renunciates who have not yet been fully ordained, (5) upāsakā: laymen, (6) upāsikā: laywomen, and (7) śikṣamāṇā: a śramaṇerī between the age of 18 and 20 who maintains the six precepts. The saṃgha was run using a consensus system.

“Dependent origination” is the basis of [the] “no-self” concept. It is a fundamental part of Śākyamuni’s teachings, unique to the Buddha, and is not found in Hindu schools. The term “dependent origination” is a translation of the Sanskrit “pratītyasamutpāda.” “Pratītya” means “condition” and “samutpāda” means “to arise together.” Dependent origination holds that all beings arise based on conditions. They come into being and are mutually dependent. This was the antithesis of the theory, generally accepted in India, that everything comes into existence based on the ātman or self.

This idea of dependent origination developed into teachings such as the “twelvefold chain of dependent origination,” which describes the cause of suffering in this world and the conditions for its extinction. It holds that (1) ignorance, (2) volitional formations, (3) consciousness, (4) name and form, (5) the six sense bases, (6) contact or impression, (7) feeling or sensation, (8) craving or desire, (9) clinging or attachment, (10) becoming or existence, (11) birth, and (12) old age and death, each of these arise due to the link that comes before it. This way of looking at the twelve links is called anuloma or “sequential observation.” Observing that volition is extinguished when ignorance is extinguished, and that extinguishing the suffering of old age and death comes from extinguishing ignorance is called pratiloma or “reverse observation.”

The aim of Buddhism is for each being to obtain bodhi or awakening, and thus become a buddha. A buddha is someone who has obtained bodhi. Someone who strives to obtain bodhi is called a “bodhisattva.” The final awakening for which Buddhists should aim is called Anuttara-samyak-saṃbodhi or “unsurpassed, perfect, and complete awakening.”

Awakening is also described as mokṣa, which means liberation or freedom. It means to be liberated from a transmigratory mode of being and not reborn in the world of existence. While Indian thought generally saw the source of liberation as the physical body, Buddhism saw liberation as being mental because one is liberated from mental afflictions and reaches a free state of mind.

This state was called nirvāṇa: a peaceful liberated state in which the flames of delusion are blown out. Nirvāṇa literally means “to be blown out.” When Śākyamuni passed away, it appeared that the fire of his life had been blown out, which led people to describe the extinction of body and mind as nirvāṇa. Two teachings subsequently appeared. The first was “nirvāṇa with remainder,” a nirvāṇa in which while living one extinguishes delusion and the body remains. The second is “nirvāṇa without remainder,” a complete nirvāṇa in which delusions have been extinguished and one has fully left behind the restrictions of existence. In Mahāyāna Buddhism, there is also said to be the “nirvāṇa of non-abiding,” in which even though one has obtained enlightenment and is not stuck in the world of life and death, for the benefit of sentient beings one remains in the world of life and death, and does not enter a nirvāṇa separate from the world.

Śākyamuni did not incorporate atman into his teachings. Rather, he preached anātman or “no-self.” He rejected the idea that various beings exist because of each having an ātman as their absolute foundation. Instead, he taught the “five aggregates” as the foundation of existence. These are: (1) form or flesh, (2) feeling or sensory function, (3) perception or the representative function, (4) mental formations, volition or will, and (5) consciousness or awareness. He explained that individual humans come into existence based on the mutual dependence of these five elements. To this notion of the “five aggregates” he added two more categories to form what are called the “three categories.” The next category is the “twelve sense fields” comprised of two groups. The six sense bases: eyes, ears, nose, tongue, body, and mind, and their six objects: shape and color, sound, scent, flavor, physical feeling, and mental presentation. The last category contains the six consciousnesses of visual consciousness, auditory consciousness, olfactory consciousness, gustatory consciousness, tactile consciousness, and mental consciousness. The last two categories are also called the “eighteen elements”: twelve sense fields and six consciousnesses.

Grateful for these teachings, the five bhikṣus embraced Śākyamuni as their teacher and became disciples, thereby forming the first Saṃgha, a group of renunciates who adopted the precepts and rules for monastic discipline and had the same goal. This thereby put in place the “Three Jewels” in which Buddhists take refuge: the Buddha, Dharma, and Saṃgha. The Three Jewels are defined in several ways, including (1) as being separate and individual entities, (2) as being individual entities that are unified in essence, namely, the Buddha’s unsurpassed truth, pure merit, and harmonized merit, and (3) as concretely existing in this world in the form of Buddha statues, sūtras, and the saṃgha. Furthermore, saṃgha can be defined as a “manifest saṃgha,” comprised of five or more renunciates who live in the same area. It can also be understood to mean the “saṃgha in the four directions,” or all Buddhist monastics.

The Four Seals of the Dharma: (1) All phenomena are impermanent. In other words, they change. (2) All existences are without a self; they do not have an unchanging essence. (3) Nirvāṇa is quiescent. The state that is without delusion is peaceful and tranquil. (4) All phenomena are suffering. …

Five Aggregates: Five accumulations that are the elements comprising the world of phenomena. (1) Form: All matter. (2) Feeling: The sensory functions. (3) Perception: The unified functioning of the sensory organs. Imagination. Perceiving that which is reflected in one’s mind. (4) Volition: Connecting representations and internal consciousness. The power of formation. (5) Consciousness: Unifying all the functions of consciousness. Self-reflective awareness.

No-self: The insight that a self does not exist on an absolute level. One of Buddhism’s basic theories regarding the perception of reality.

The Noble Eightfold Path: (1) Right View of the Dharma: Working to not fall into biased or partial views. (2) Right Thought Regarding the Dharma: That which is the basis of, for example, judgments and decisions. The karma or action of thought. This is one of the three karmas. (3) Right Speech about the Dharma: Words and actions in accordance with the Dharma. The karma of speech, another of the three karmas. (4) Right Action: Carrying out properly and acting in accordance with the Dharma. This is restrictive. It is the karma of deeds, the last of the three karmas.
(5) Right Living: Making the Dharma one’s life. Maintaining a rhythm in daily life and not falling into laziness. (6) Right Effort to Practice the Dharma: Maintaining the precepts and rules for discipline while properly engaging in religious training. (7) Right Mindfulness regarding the Dharma: Maintaining one’s consciousness in a proper state. (8) Right Concentration: Properly maintaining one’s mind in a receptive state for the Dharma. This is meditative concentration.